1. Field of the Invention
The present invention relates generally to pipe saddle assemblies and more particularly to a cartridge insert pipe saddle assembly of particular design.
2. Description of Prior Art
Pipe saddle assemblies or service saddles as they are commonly called have been used in the underground utility field for a considerable number of years. These saddles, which take on various configurations, are principally used as a branch connection in tap connecting a secondary transmission line, commonly referred to as a service lateral, to an existing distribution or transmission line. A typical service saddle provided heretofore includes an outlet body or outlet arrangement for seal connecting the service lateral in fluid communication with a tap-in opening provided in the wall of the existing line and one or more straps for holding the outlet arrangement in place.
Most service saddles must meet stringent durability requirements and, as a result, the major component of these saddles, i.e. the outlet arrangement, as furnished over the years, has been constructed of one piece heavy cast copper alloy or cast ductile or malleable iron. The heavy-duty outlet arrangement of this type is generally bolted to the distribution or transmission line by means of the aforestated strap passing around the underside of the line and is equipped with an integral threaded outlet opening. This threaded outlet opening is designed to receive a threaded complementary valve or other such component for connecting the service lateral to the main line. Because the size and thread design of the threaded outlet opening depends on the size of the main line and the size and thread design of the service lateral, it has heretofore been necessary to stock a large number of different saddle assemblies with different threaded openings. In fact, in many cases it has heretofore been necessary to stock approximatey eleven commonly used saddle assemblies of differing sizes for each distribution or transmission line size. In some instances corrosion is a problem and non-ferrous or special corrosion resisting materials such as copper base alloys must be used. For this reason the number of service saddles required in stock can increase two or three-fold for each distribution or transmission size.
Obviously, the aforediscussed requirement to stock a large number of service saddles of different sizes increases record keeping, inventory costs, necessitates the need for added space and ultimately increases the per unit cost of the saddles. Another factor which increases the cost of the service saddles of the above-described type resides particularly in the utilization of the integral threaded outlet. More specifically, it is extremely difficult and time-consuming to drill and tap these threaded openings in the heavy cast material comprising the heretofore provided outlet arrangement. This is especially true where the saddle is used for connecting a relatively large service lateral to a main line, thereby requiring a relatively large threaded outlet opening.
Attempts have been made over the years to use outlet arrangements having threaded inserts, particularly plastic inserts, to avoid the necessity of tapping these large castings and stocking arrangements of various sizes. However, it has been found that these insert-type outlet arrangements have not been completely satisfactory for their intended purpose. One very serious drawback with the insert-type outlet arrangements (and integral cast arrangements) provided heretofore is that they are not designed to provide a reliable fluid seal around the tap-in opening in the main line. As will be seen hereinafter, the present invention is directed to a cartridge insert saddle assembly which, along with other advantages, overcomes this serious drawback.
As stated above, a typical service saddle provided heretofore includes an outlet body or outlet arrangement and one or more straps for securing the outlet arrangement to the distribution or transmission line. In this regard, the service saddle, as also stated above, typically includes a pair of lugs connected with and located on opposite sides of the outlet arrangement for each strap. These lugs include openings through which opposite threaded end segments of the strap can pass. The straps are interlocked to the lugs by means of cooperating nuts thread mounted to the ends of the straps after the ends have been passed through the openings.
It should be apparent that these typically constructed lugs and straps require that the nuts be completely removed from the strap end segments before the latter can be inserted into the openings in the lugs. At first glance, this may appear to be of minor consequence. However, it should be pointed out that the saddles are generaly assembled in the field and usually in a highly confined area within a ditch where the main transmission or distribution line is located. It is often difficult, especially in cold weather, to manipulate the nuts around the threaded ends of the straps making it quite possible to lose the nuts in the somewhat loose dirt under the main line within the ditch. As will be seen hereinafter, the saddle assembly of the present invention is also directed to overcome this problem of assembly.